This invention relates to an automated apparatus for lining the inner wall of a vessel with bricks. More particularly, this invention relates to a brick laying apparatus comprising a work platform which is vertically movable within the vessel and capable of rotating about the vertical axis of the latter. The work platform is provided with two brick-pallet storage areas and with automatic brick manipulating and laying means.
Although not being limited thereto in its utility, the present invention is aimed more particularly at an apparatus for laying a refractory lining on the inner wall of a metallurigical convertor.
Various apparatuses of this type (see, for example, German Patent Document No. DE-AS-1, 154, 131 and Belgium Patent No. BE-A-760,355) have already been proposed for the purpose of automatically carrying out a job (bricklaying in a metallurigical vessel) which has heretofore usually been carried out manually under extremely difficult conditions.
Unfortunately, the proposed apparatuses have not solved all of the outstanding problems, and consequently, even now, it is still not possible to achieve the benefits associated with complete automation of the operation of lining convertors with bricks.
In this respect, it will be appreciated that the bricks have a tapered conical shape, so that they can be laid in a circle in accordance with the cross-section of the convertor. It will further be appreciated that not only are all convertors not of the same size, but also the diameter of each convertor varies according to its height (because convertors usually have a substantially oval vertical cross-section). Since it is difficult to make bricks to measure, two specific types of bricks of differing conicity are manufactured. By carefully alternating between these two types, the desired curvatures of a particular convertor are obtained. That means that two pallets of bricks (one of each type), must be continuously available on the work platform, so that the robot laying the bricks can automatically make the proper selection according to an automatic bricklaying control.
The brick pallets are raised or lowered on the platform by means of a hoist, and once the pallets are level with the platform, are loaded onto a movable carriage which shifts the pallets horizontally onto their respective storage areas. To ensure that the apparatus can function correctly in an automated manner, each brick pallet must always be placed at a very precise location; and the bricks must always be arranged on the pallets accurately and in the same way; and must always be oriented in the same way relative to one another and relative to the platform and to the manipulating robot. This condition becomes even more complicated because the platform must be capable of rotating about the vertical center axis of the vessel to allow the robot to reach the entire brick-lining circumference. Consequently, the system for moving the pallets must function accurately and in a constant manner, without any jolting, in order to prevent the bricks from being shifted on the pallets and possibly falling therefrom. Moreover, the system must be associated with detection means for continuously monitoring the correct position of the pallets and bricks.
Another problem with automatic bricklaying apparatuses is the overcrowding of the platform. When the pallets are raised on the platform, the hoists and winches provided for this purpose are installed on the platform. The pulleys and cables associated with the hoists and winches impede the movement of the manipulating robot and are a constant danger to the personnel located on the platform.
The empty pallets can also cause problems of overcrowding. In fact, when a full pallet is raised or lowered on the platform, the empty pallet first must be removed so that the full pallet can be transferred onto the carriage, before the empty carriage is attached to the hoist in order to be carried away. Another possibility would be to lower the empty pallet first before raising a full pallet, but this is undesirably time consuming.